Prior to now, color liquid crystal displays have been widely applied to people's life and production, wherein color display characteristic and visual angle characteristic of the liquid crystal displays are important display indexes which are taken more and more attention.
In terms of the color display characteristic, a technical means utilized by the prior liquid crystal display device is to dispose a color filter made by resin material so as to accomplish the color display characteristic. Each one of color pixels in the color filter corresponds to one color among three primary colors such as red, green and blue. When the back light emits the lights of which spectrum range covers three colors of red, blue and green, due to filter action of the resin material, the color pixels having one certain color allow lights having corresponding color to permeate and absorb the lights having the other two colors so as to accomplish the color display characteristic of the liquid crystal display. Although this technology accomplishes the color display, it has a problem that light utilization efficiency decreases sharply. The reasons is as follows: at one hand, light filtering action of the color filter makes most lights emitted by the back light be absorbed, and the light utilization efficiency is less than ⅓; at the other hand, because all the back lights belonging to fluorescent lamp type emit lights by stimulating the fluorescent powder coated on the lamp tube wall via ultraviolet rays, and back lights belonging to white LED type emit lights by stimulating the fluorescent powder coated on the lamp tube wall via shortwave light projected from the diode chip, namely via the purple lights or the blue lights emitted, therefore, light energy consumption phenomenon caused by stimulating the fluorescent material to emit lights exist in all the prior back lights. The conventional color liquid crystal display exists at least two times of light energy consumptions, thus the energy utilization efficiency will decreased sharply, which not only results the luminance of the liquid crystal display is low, but also the energy used for ensuring the display luminance will be higher.
In terms of the visual angle characteristic, the liquid crystal display generally adopts birefringence technology or optical rotation technology to control light intensity. Limited to the working principle of displaying of liquid crystal display, the lights, after emitted by the back light, will orderly pass through a lower polarizer, a liquid crystal layer and an upper polarizer. Under the incline action of the liquid crystal molecules, the optical path difference among the lights having various incident angles is different, and the result is that visual angle of the liquid crystal display generally is narrower. So called visual angle, it is a visual range in which people could normally observe image luminance, contrast and color on the screen of the liquid crystal display. The narrow visual angle will result in that the contrast and color of images deviate when the viewer views the images with a much larger angle. Thus, compared with an active emitting light display apparatus, the visual angle characteristic of the prior liquid crystal display is worse. In order to solve the above problem, the prior technologies develop many modes, such as optical membrane compensation mode, multi-domain vertical alignment (MVA) mode, patterned vertical alignment (PVA) mode, in-plane switching (IPS) mode, fringe field switch (FFS) mode, to improve the visual angle characteristic of the liquid crystal display. However, the above technology could only reduce the difference between the paths of the lights having various incident angles, rather than eliminate the difference completely. The improvement to the vision is also finite. The above modes make the structure of the liquid crystal display complex so the difficulty for process is increased.